The present invention generally relates to a tractor having a cab riser bracket assembly and an associated method of mounting the bracket assembly on the tractor.
Material handling machines, such as grapple tractors (hereinafter referred to as tractors), are typically used in projects which require the movement of significant amounts of scrap, such as ferrous materials. These types of tractors generally include a grapple or magnet operatively linked to a boom and arm. Hereinafter, the boom and arm is collectively referred to as the grapple arm. The primary function of the grapple arm is to move the grapple in such a manner that it can grasp and transfer the scrap from one location to another. These types of tractors also include a cab that houses the operator and the controls used to direct the movements of the grapple arm, and therefore the grapple.
These tractors are often used to load or unload scrap from truck beds or from barges. However, using such tractors to perform the aforementioned loading or unloading function has a significant drawback. That is, it is very difficult for the operator of the tractor to see down into the truck bed or barge from his or her position in the cab. The operator's inability to see down into the truck bead or barge impedes his or her ability to properly control the movement of the grapple arm and grapple. As a result, the operator's ability to efficiently operate the grapple arm and grapple decreases.
In order to overcome the above described problem, several tractor models are constructed to include an adjustable cab riser apparatus. Such an apparatus allows the operator of the tractor to raise the cab to the desired height above the tractor body. Having the cab positioned at an appropriate height above the tractor body allows the operator to see into the truck bed, barge or container being loaded or unloaded, and therefore facilitates the proper control of the grapple arm and grapple.
Some cab riser apparatus are constructed to include a large unitary bracket member directly welded onto the frame of the tractor body. These apparatus also include a hydraulic cylinder and a number of support arms. The hydraulic cylinder and support arms are connected to the bracket member and a brace. The brace is connected to a platform member for supporting the tractor cab. Generally, the aforementioned cab riser components are arranged such that the actuation and extension of the hydraulic cylinder causes the brace, platform member, and therefore the tractor cab, to rise above the tractor body to a desired height. However, as will be discussed below, present cab riser apparatus suffer from several drawbacks.
One problem with the above described arrangement is that the large unitary bracket used to mount the above described components is difficult to fabricate and handle during the construction of the cab rising apparatus. For example, fabricating a large component is more complex and costly than fabricating two smaller components. Moreover, once the large unitary bracket used by the prior art is welded onto the tractor body, the body becomes more difficult to handle. For instance, the body becomes cumbersome to move from one location to another within the manufacturing facility.
Another problem with certain types of brackets used to mount cab rising apparatus relates to the ease in which they can be mounted onto a tractor body. As discussed above, many prior art brackets are directly welded onto the tractor body. Since these brackets are typically large and cumbersome, the welding process is difficult. Furthermore, once the bracket is welded onto the body, the bracket's spatial relationship to the body is fixed. Therefore, no convenient adjustment of the bracket's position relative to the body is possible. This is a significant drawback since, in many cases, adjustment of the bracket is required for the cab riser apparatus to work properly.
Additional problems with prior art cab riser apparatus include (1) their inability to be retrofit onto tractor bodies; (2) they are relatively bulky, and thus require a significant amount of space; and (3) they tend to be relatively unstable in the raised position and thus cause the cab to "wobble" or move around during use of the tractor.
Therefore, in light of the above discussion, it is apparent that a bracket assembly for mounting a cab rising apparatus which is easy to manufacture and handle is desirable. The present invention provides such a bracket assembly. The bracket assembly of the present invention includes a relatively small weld group welded onto the frame of the tractor body. The bracket of the bracket assembly is then bolted onto the weld group, rather than being welded directly to the frame.
In use, the present invention provides a bracket assembly which is relatively easy to fabricate and handle during the construction of a cab rising apparatus. Moreover, the present invention provides a bracket assembly which allows the position of the bracket to be adjusted after mounting. In addition, the present invention provides a bracket assembly that can be retrofit onto tractor bodies.